Re: [PATCHv4 18/43] block: define BIO_MAX_PAGES to HPAGE_PMD_NR if huge page cache enabled

[Christoph Hellwig]

On Tue, Oct 25, 2016 at 10:13:13PM -0600, Andreas Dilger wrote:
> Why wouldn't you have all the pool sizes in between?  Definitely 1MB has
> been too small already for high-bandwidth IO.  I wouldn't mind BIOs up to
> 4MB or larger since most high-end RAID hardware does best with 4MB IOs.

I/O sizes are not limited by the bio size, we can already support larger
than 1MB I/O for a long time.